llvm-6502/include/llvm/Debugger/SourceFile.h

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//===- SourceFile.h - Class to represent a source code file -----*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the SourceFile class which is used to represent a single
// file of source code in the program, caching data from the file to make access
// efficient.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_DEBUGGER_SOURCEFILE_H
#define LLVM_DEBUGGER_SOURCEFILE_H
#include "llvm/System/Path.h"
#include "llvm/System/MappedFile.h"
#include <vector>
namespace llvm {
class GlobalVariable;
class SourceFile {
/// Filename - This is the full path of the file that is loaded.
///
sys::Path Filename;
/// Descriptor - The debugging descriptor for this source file. If there
/// are multiple descriptors for the same file, this is just the first one
/// encountered.
///
const GlobalVariable *Descriptor;
/// This is the memory mapping for the file so we can gain access to it.
sys::MappedFile File;
/// LineOffset - This vector contains a mapping from source line numbers to
/// their offsets in the file. This data is computed lazily, the first time
/// it is asked for. If there are zero elements allocated in this vector,
/// then it has not yet been computed.
mutable std::vector<unsigned> LineOffset;
public:
/// SourceFile constructor - Read in the specified source file if it exists,
/// but do not build the LineOffsets table until it is requested. This will
/// NOT throw an exception if the file is not found, if there is an error
/// reading it, or if the user cancels the operation. Instead, it will just
/// be an empty source file.
SourceFile(const std::string &fn, const GlobalVariable *Desc)
: Filename(fn), Descriptor(Desc), File() {
std::string ErrMsg;
if (File.open(Filename, sys::MappedFile::READ_ACCESS, &ErrMsg))
throw ErrMsg;
readFile();
}
~SourceFile() {
File.unmap();
}
/// getDescriptor - Return the debugging decriptor for this source file.
///
const GlobalVariable *getDescriptor() const { return Descriptor; }
/// getFilename - Return the fully resolved path that this file was loaded
/// from.
const std::string &getFilename() const { return Filename.toString(); }
/// getSourceLine - Given a line number, return the start and end of the
/// line in the file. If the line number is invalid, or if the file could
/// not be loaded, null pointers are returned for the start and end of the
/// file. Note that line numbers start with 0, not 1. This also strips off
/// any newlines from the end of the line, to ease formatting of the text.
void getSourceLine(unsigned LineNo, const char *&LineStart,
const char *&LineEnd) const;
/// getNumLines - Return the number of lines the source file contains.
///
unsigned getNumLines() const {
if (LineOffset.empty()) calculateLineOffsets();
return LineOffset.size();
}
private:
/// readFile - Load Filename into memory
///
void readFile();
/// calculateLineOffsets - Compute the LineOffset vector for the current
/// file.
void calculateLineOffsets() const;
};
} // end namespace llvm
#endif